Python Flask Monitoring DevOps

Uptime Monitor

Background thread pings the portfolio API and site every 60 seconds, recording response times. This page graphs the last 24 hours of data : pulled live from the server.

Ping interval60 seconds

History24 hours

BackendFlask + threading

StorageJSON file

GitHub →

Live Dashboard

Auto-refreshes every 30 seconds. Chart shows response time in ms over 24 hours.

Loading uptime data…

How it works

Thread starts

Daemon thread launches with the Flask app via gunicorn

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Ping loop

Every 60s: HTTP GET to each target, record status + ms

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Store

Append to JSON file, keep last 1440 entries (24h)

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Serve

/api/uptime returns history; frontend draws Canvas chart

Decisions

Daemon thread, not cron

A daemon thread in the same process is simpler than a separate cron job. It dies with the app : no orphan processes, no separate deployment step.

JSON file, not a database

24 hours of 1-minute checks is ≈1440 entries per target : trivially small. A JSON file avoids a database dependency and is easy to inspect manually.

Canvas, not a chart library

Chart.js or D3 would be overkill for a single line chart. Drawing directly on Canvas keeps the page at zero dependencies.

Atomic file writes

Writes go to a temp file first, then os.replace() swaps atomically. Prevents corrupted reads if the API serves during a write.